1. Field of the Invention
The present invention relates to an apparatus for dividing body tissue, and more particularly to such an apparatus which may be employed to ligate and divide tubular vessels in endoscopic surgical procedures.
2. Background of the Art
Apparatus for ligating and dividing organic tubular structures (e.g., blood vessels and the like) are known and are commonly used in various surgical operations such as esophageal and gastric procedures. Generally such apparatus have a means for grasping the tubular structure, means for ligating the structure in two locations, usually by the application of staples, clips or the like, and means for dividing the tubular structure between the ligated portions, usually by slicing it with a knife.
U.S. Pat. No. 3,665,924 describes a ligating and dividing instrument which includes a cartridge for housing a plurality of staples. The instrument operates in three stages: after the tubular structure is inserted between the jaws of the cartridge, the cartridge jaws close, a pair of pushers come forward and suture the organic structure in two spaced locations with a pair of surgical staples, and a blade comes forward and divides the tubular structure. Other ligating and dividing instruments are disclosed in U.S. Pat. Nos. 4,086,926; 4,201,213; 4,349,028; and 4,556,058.
While the various known ligating and dividing apparatus have provided beneficial features to surgeons in the performance of non-endoscopic surgical operations, they are not useful in endoscopic or laparoscopic procedures. In laparoscopic procedures surgery is performed in the interior of the abdomen through a small incision. An endoscopic operation is one in which a surgical procedure is carried out in any hollow viscus of a human (or animal) body by means of instrumentation for operating or viewing deployed through one or more tubes. In either laparoscopic or endoscopic surgery, the functional portion of the instrumentation is manipulated or controlled from outside the body. Laparoscopic and endoscopic procedures generally require that any instrumentation inserted into the body be sealed, i.e., provisions must be made to ensure that gases do not enter or exit the body through the laparoscopic or endoscopic incision as, for example, in surgical procedures in which the surgical region is insufflated. Laparoscopic and endoscopic procedures often require the surgeon to operate on organs, tissue, and vessels far removed from the site of the incision, thereby requiring that any instruments to be used in such procedures be both long and narrow. Mechanical actuation of such instruments is for the most part constrained to movement of the various components along a longitudinal axis, even if lateral movement is employed at the operating site. The initial opening in the body tissue to allow passage of the endoscopic tube to the interior of the body can be a natural passageway of the body (e.g. bronchial tubes), or it can be a puncture produced by a tissue piercing instrument such as a trocar. Because the endoscopic tubes, instrumentation, and any required puncture are relatively narrow, endoscopic surgery is less invasive and causes much less trauma to the patient as compared with surgery in which the surgeon is required to cut open large areas of body tissue. It would be advantageous to have an endoscopic ligating and dividing instrument, and we have developed an apparatus to meet this need.